:root {
  color-scheme: light;
  --ink: #142326;
  --muted: #66777b;
  --line: #d8e2df;
  --paper: #f7faf8;
  --panel: #ffffff;
  --teal: #2f6f73;
  --teal-deep: #1e5155;
  --coral: #d86a4a;
  --yellow: #f3bf46;
  --green: #5d8d5a;
  --blue: #476eaa;
  --shadow: 0 18px 48px rgba(29, 55, 58, 0.12);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--paper);
  color: var(--ink);
  font-family: Inter, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
}

button,
input {
  font: inherit;
}

button {
  cursor: pointer;
}

.app-shell {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  min-height: 100vh;
}

.sidebar {
  display: flex;
  flex-direction: column;
  gap: 24px;
  padding: 28px 20px;
  background: #173b3f;
  color: #f8fffc;
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand-mark {
  display: grid;
  width: 44px;
  height: 44px;
  place-items: center;
  border-radius: 8px;
  background: var(--yellow);
  color: #173b3f;
  font-weight: 900;
}

.eyebrow {
  margin: 0 0 6px;
  color: inherit;
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0;
  opacity: 0.68;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 0;
  font-size: 24px;
}

h2 {
  margin-bottom: 0;
  font-size: clamp(24px, 3vw, 36px);
}

h3 {
  margin-bottom: 0;
  font-size: 20px;
}

.today-heading {
  font-size: 26px;
}

.tabs {
  display: grid;
  gap: 8px;
}

.tab {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  min-height: 44px;
  padding: 10px 12px;
  border: 1px solid transparent;
  border-radius: 8px;
  background: transparent;
  color: rgba(248, 255, 252, 0.78);
  text-align: left;
}

.tab.active,
.tab:hover {
  border-color: rgba(255, 255, 255, 0.16);
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
}

.tab-icon {
  display: grid;
  width: 24px;
  height: 24px;
  place-items: center;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.12);
  font-weight: 800;
}

.exam-box {
  margin-top: auto;
  padding: 16px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.08);
}

.exam-box strong {
  display: block;
  margin-bottom: 4px;
  font-size: 34px;
}

.exam-box span {
  color: rgba(248, 255, 252, 0.72);
  font-size: 13px;
}

.workspace {
  min-width: 0;
  padding: 28px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 24px;
}

.topbar-actions,
.toolbar-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.date-control {
  display: grid;
  gap: 4px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
}

.date-control input {
  min-height: 40px;
  padding: 0 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--ink);
}

.sync-status {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  padding: 0 10px;
  border: 1px solid rgba(47, 111, 115, 0.25);
  border-radius: 999px;
  background: #edf7f4;
  color: var(--teal-deep);
  font-size: 12px;
  font-weight: 850;
  white-space: nowrap;
}

.view {
  display: none;
}

.view.active {
  display: block;
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
  margin-bottom: 18px;
}

.metric-card,
.panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: var(--shadow);
}

.metric-card {
  min-height: 132px;
  padding: 18px;
}

.metric-card.alert {
  border-color: rgba(216, 106, 74, 0.38);
}

.metric-label {
  display: block;
  margin-bottom: 12px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 800;
}

.metric-card strong {
  display: block;
  margin-bottom: 8px;
  font-size: 32px;
}

.metric-card small,
.task-meta,
.quiz-meta,
.file-item small {
  color: var(--muted);
}

.split-layout,
.quiz-layout,
.library-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(320px, 0.65fr);
  gap: 18px;
}

.panel {
  padding: 18px;
}

.panel-heading,
.toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 16px;
}

.compact-heading {
  margin-top: 18px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.toolbar {
  margin-bottom: 18px;
}

.primary-action,
.secondary-action,
.icon-button,
.segment {
  min-height: 40px;
  padding: 0 14px;
  border-radius: 8px;
  border: 1px solid transparent;
  font-weight: 800;
}

.small-action {
  min-height: 34px;
  padding: 0 12px;
  font-size: 13px;
}

.favorite-question.active {
  border-color: rgba(216, 106, 74, 0.45);
  background: rgba(216, 106, 74, 0.1);
  color: #9c442e;
}

.primary-action {
  background: var(--teal);
  color: #fff;
}

.primary-action:hover {
  background: var(--teal-deep);
}

.secondary-action,
.icon-button,
.segment {
  border-color: var(--line);
  background: #fff;
  color: var(--ink);
}

.icon-button {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.segmented {
  display: inline-flex;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #eef4f1;
}

.segment {
  border-color: transparent;
  background: transparent;
}

.segment.active {
  background: #fff;
  box-shadow: 0 4px 14px rgba(29, 55, 58, 0.08);
}

.task-list,
.quiz-list,
.plan-container,
.file-list {
  display: grid;
  gap: 10px;
}

.task-item,
.quiz-card,
.plan-item,
.file-item {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.task-item {
  display: grid;
  grid-template-columns: 24px minmax(0, 1fr) auto auto;
  gap: 12px;
  align-items: center;
  padding: 14px;
}

.task-item input {
  width: 18px;
  height: 18px;
  margin-top: 3px;
  accent-color: var(--teal);
}

.task-item input:disabled {
  cursor: not-allowed;
}

.task-title {
  margin-bottom: 6px;
  font-weight: 850;
}

.subject-pill {
  display: inline-flex;
  align-items: center;
  min-height: 24px;
  padding: 0 8px;
  border-radius: 999px;
  background: #edf5f3;
  color: var(--teal-deep);
  font-size: 12px;
  font-weight: 850;
}

.material-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 34px;
  padding: 0 12px;
  border: 1px solid rgba(47, 111, 115, 0.28);
  border-radius: 8px;
  background: #edf7f4;
  color: var(--teal-deep);
  font-size: 13px;
  font-weight: 900;
  text-decoration: none;
  white-space: nowrap;
}

button.material-action {
  cursor: pointer;
}

.task-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: flex-end;
}

.material-action:hover {
  border-color: rgba(47, 111, 115, 0.55);
  background: #dff1ed;
}

.material-action.disabled {
  border-color: var(--line);
  background: #f3f6f5;
  color: var(--muted);
}

.hidden {
  display: none !important;
}

.lesson-check {
  margin-top: 16px;
  padding: 16px;
  border: 1px solid rgba(47, 111, 115, 0.22);
  border-radius: 8px;
  background: #f7fbfa;
}

.lesson-check-head,
.lesson-check-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
}

.lesson-check-head {
  margin-bottom: 14px;
}

.lesson-check-foot {
  position: sticky;
  bottom: 0;
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  background: #f7fbfa;
  color: var(--muted);
  font-weight: 800;
}

.lesson-question-list {
  display: grid;
  gap: 10px;
}

.lesson-question {
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.lesson-question fieldset {
  display: grid;
  gap: 8px;
  margin: 12px 0 0;
  padding: 0;
  border: 0;
}

.icon-only {
  display: grid;
  width: 36px;
  height: 36px;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
  font-size: 22px;
  font-weight: 800;
}

.primary-action:disabled,
.secondary-action:disabled {
  cursor: not-allowed;
  opacity: 0.55;
}

.phase-track {
  display: grid;
  gap: 12px;
}

.phase-row {
  display: grid;
  grid-template-columns: 82px minmax(0, 1fr) 48px;
  gap: 10px;
  align-items: center;
}

.phase-bar {
  height: 12px;
  overflow: hidden;
  border-radius: 999px;
  background: #e7efed;
}

.phase-fill {
  height: 100%;
  border-radius: inherit;
}

.plan-item {
  padding: 14px;
}

.plan-head {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}

.plan-tasks {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.mini-task {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  max-width: 100%;
  padding: 0 10px;
  border-radius: 999px;
  background: #f0f5f6;
  color: #23474a;
  font-size: 13px;
  font-weight: 700;
}

.quiz-card {
  padding: 16px;
}

.quiz-card fieldset {
  display: grid;
  gap: 8px;
  margin: 12px 0 0;
  padding: 0;
  border: 0;
}

.option {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.option.correct {
  border-color: rgba(93, 141, 90, 0.5);
  background: rgba(93, 141, 90, 0.1);
}

.option.wrong {
  border-color: rgba(216, 106, 74, 0.5);
  background: rgba(216, 106, 74, 0.1);
}

.question-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px;
  margin-top: 12px;
}

.explanation {
  display: none;
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.explanation.visible {
  display: block;
}

.score-panel {
  align-self: start;
}

.score-ring {
  display: grid;
  width: 180px;
  height: 180px;
  margin: 18px auto;
  place-items: center;
  border-radius: 50%;
  background: conic-gradient(var(--teal) var(--score-angle, 0deg), #e3ece9 0);
}

.score-ring span {
  display: grid;
  width: 130px;
  height: 130px;
  place-items: center;
  border-radius: 50%;
  background: #fff;
  font-size: 34px;
  font-weight: 900;
}

.mock-map {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
  margin-bottom: 16px;
}

.mock-start-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: 16px;
}

.mock-console {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto auto;
  gap: 16px;
  align-items: center;
  margin-bottom: 16px;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  box-shadow: var(--shadow);
}

.mock-console-metrics {
  display: flex;
  gap: 10px;
}

.mock-console-metrics span {
  display: grid;
  min-width: 90px;
  min-height: 62px;
  place-items: center;
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f7faf8;
}

.mock-console-metrics strong {
  font-size: 22px;
}

.mock-console-metrics small {
  color: var(--muted);
  font-size: 12px;
  font-weight: 800;
}

.mock-section {
  display: grid;
  gap: 10px;
}

.mock-section-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
}

.mock-pager {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 10px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 800;
}

.mock-section + .mock-section {
  margin-top: 16px;
}

.mock-section-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #eef4f1;
}

.mock-section-head span {
  color: var(--muted);
  font-size: 13px;
  font-weight: 800;
}

.knowledge-tile {
  min-height: 86px;
  padding: 14px;
  border: 1px solid var(--line);
  border-left: 5px solid var(--teal);
  border-radius: 8px;
  background: #fff;
}

.knowledge-tile strong {
  display: block;
  margin-bottom: 8px;
}

.dropzone {
  display: grid;
  min-height: 180px;
  place-items: center;
  padding: 20px;
  border: 2px dashed #9db7b0;
  border-radius: 8px;
  background: #f2f8f5;
  text-align: center;
}

.dropzone input {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
}

.dropzone span {
  display: inline-flex;
  align-items: center;
  min-height: 42px;
  padding: 0 18px;
  border-radius: 8px;
  background: var(--teal);
  color: #fff;
  font-weight: 900;
}

.dropzone small {
  display: block;
  margin-top: 10px;
  color: var(--muted);
}

.file-item {
  padding: 12px;
}

.material-summary {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 14px 0;
}

.material-card {
  min-height: 104px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f8fbfa;
}

.material-card strong {
  display: block;
  margin-bottom: 8px;
  font-size: 22px;
}

.material-card small {
  color: var(--muted);
}

.material-list {
  display: grid;
  gap: 8px;
  max-height: 320px;
  overflow: auto;
  padding-right: 2px;
}

.code-sample {
  overflow: auto;
  min-height: 286px;
  margin: 0;
  padding: 16px;
  border-radius: 8px;
  background: #10282b;
  color: #dff6ef;
  font-size: 13px;
  line-height: 1.65;
}

.toast {
  position: fixed;
  right: 20px;
  bottom: 20px;
  transform: translateY(20px);
  max-width: min(360px, calc(100vw - 40px));
  padding: 12px 14px;
  border-radius: 8px;
  background: #173b3f;
  color: #fff;
  opacity: 0;
  pointer-events: none;
  transition: 0.2s ease;
}

.toast.visible {
  transform: translateY(0);
  opacity: 1;
}

@media (max-width: 980px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: sticky;
    top: 0;
    z-index: 5;
    padding: 16px;
  }

  .tabs {
    grid-template-columns: repeat(6, minmax(0, 1fr));
  }

  .tab {
    justify-content: center;
  }

  .tab span:last-child {
    display: none;
  }

  .exam-box {
    display: none;
  }

  .summary-grid,
  .split-layout,
  .quiz-layout,
  .library-grid,
  .mock-map,
  .mock-start-grid,
  .mock-console,
  .material-summary {
    grid-template-columns: 1fr;
  }

  .mock-console-metrics {
    flex-wrap: wrap;
  }
}

@media (max-width: 680px) {
  .workspace {
    padding: 18px 14px 28px;
  }

  .topbar,
  .toolbar,
  .panel-heading {
    align-items: stretch;
    flex-direction: column;
  }

  .topbar-actions,
  .toolbar-actions {
    flex-wrap: wrap;
  }

  .summary-grid {
    grid-template-columns: 1fr;
  }

  .task-item {
    grid-template-columns: 24px minmax(0, 1fr);
  }

  .subject-pill {
    grid-column: 2;
    justify-self: start;
  }

  .material-action {
    justify-self: start;
  }

  .task-actions {
    grid-column: 2;
    justify-content: flex-start;
  }

  .lesson-check-head,
  .lesson-check-foot {
    align-items: stretch;
    flex-direction: column;
  }
}